The Santa Isabella a notorious ship that originated from somewhere in the Southern Seas. Sailors, Marines, and even Pirates, all fear it as a ghost ship of old legend. This ship is so infamous, that even the Calavera Pirates, the most powerful and feared pirate crew in the world, don't even speak its name. It's captain who's name was never revealed, was in actuality a very powerful Lich, who actually gained the benefits of being both alive and undead, by consuming countless souls over decades. His crew was made entirely of people and undead who had their souls stolen by him.
It was ultimately destroyed, and the hundreds of souls imprisoned on board were all freed.